Track-bolt



(No Model.)

C. C. WRENSHALL TRACK BOLT. 4

No. 355,112. Patented Dec. Z8, 1886..

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UNITED STATES PATENT EFICE.

CHARLES C. WRENSHALL, OF ST. PAUL, MINNESOTA.

TRAC K-BOLT.

SPECIFICATION forming part of Letters Patent No.355,112, dated December 28, 1886.

I Application tiled September 28, 1885. Serial No. 178,468. (No model.)

To all whom, it may concern:

Be it known that I, CHARLES C. WREN- sHALL, acitizen of the United States, residing i companying drawings, in which- Figure l is a side View of my bolt. Figs. 2 and 3 are cross-sections of the same, and Fig.` 4 is a View of the nut. r

Inthe use of traolebolts on a railroad, the greatest strain on the bolt is received from 'the edge of the bolt-hole in the rail when the latter seeks to move in contraction from a change of temperature, or from a continuous line of rail, seeking to move with the trains, and from which movements they are prevented by `the bolts of the splices to a large ext-ent; so

counteract the eXtra strain in this direction. The bolt is headed as usual, and the point which projects beyond the joint-plate or shplate is threaded for the reception of the nut. This point is formed' of a diameter somewhat greater than the smaller diameter of the main body or shank-that is, the amount of metal removed from the longer diameter in rounding off the point for threading is added to the smaller diameter, as fully seen in Figs. l and 3, and the strength of the bolt is thus retained as great'at the point as in the shank, and the point is then threaded as usual. This effect is readily gained by a single tap from the former7 ot' a bolt-machine, and the diameter is increased to such extent as to leave the strength unimpaired by the cutting of the thread. tion, or with a longer horizontal diameter, more effectually resists the strain of the track contractions, and the increased thickness of 3g The bolt so formed, of oval cross-secthe point retains a uniform strength throughont the article, leaving noipoints of especial kweaknessto give way under the various strains in presence of two witnesses.

CHARLES G. WRENSHALL. Witnesses:

L. AYREs, F. I. WILsEY. 

